“The Paris Agreement is a major international achievement and a key step towards reducing greenhouse gas emissions in the rapid and dramatic way we need to in order to avoid catastrophic climate change. The aspiration to cap mean global temperature rise to 1.5C, with 2C as a realistic and still achievable target, accompanied by substantial funding from the developed countries to assist developing parties to reach their mitigation targets, are essential elements of the solution. However it must be stressed that this agreement is about targets not mechanisms. The real challenge of implementation now starts and this will require further international and regional robust agreements on a realistic and binding carbon price.

“Many commentators are saying that this agreement signals the end of fossil fuels. Whilst this must be the long-term goal, it will only be achieved well into the second half of this century. Most countries, including the UK but especially developing parties, will need to continue to use fossil fuels to meet their energy demands and maintain/grow the quality of life of their citizens. The Paris CO2 reduction targets can still be met whilst continuing to use fossil fuels as long as we rapidly implement carbon capture and storage (CCS) on a massive global scale (about 5000 2Mte CO2 pa systems by 2050). This demanding target can still be met, driven by a realistic carbon price, but makes the recent UK government decision to scrap the £1bn Peterhead and White Rose CCS projects seem even more short-sighted and irresponsible in the light of the Paris agreement, which it strongly supports.”

Prof. Kevin Anderson, Tyndall Centre, Manchester University, said:

“The Paris Agreement is a fitting testament to how years of diligent and meticulous science has ultimately weathered relentless and well-funded attempts to undermine its legitimacy. Under the inspiring auspices of the French people, the global community has come together as never before to tackle what is probably the first truly globalised and self-induced challenge to humanity.

However, whilst the 2°C and 1.5°C aspirations of the Paris Agreement are to be wholeheartedly welcomed, the thirty-one page edifice is premised on future technologies removing huge quantities of carbon dioxide from the atmosphere many decades from today. If such highly speculative ‘negative emission technologies’ prove to be unsuccessful then the 1.5°C target is simply not achievable. Moreover, there is only a slim chance of maintaining the global temperature rise to below 2°C.

“Staying below the 2°C commitment demands levels of reductions in emissions far beyond anything discussed during the Paris negotiations. If we are serious about climate change, the 10% of the global population responsible for 50% of total emissions need to make deep and immediate cuts in their use of energy – and hence their carbon emissions. In addition, the huge and growing emissions from aviation and shipping, currently exempt from the Paris negotiations, need to be included for there to be any meaningful control over climate change in line with 2°C.

“The inclusion of a 40Gt figure for 2030 as being in accordance with the 2°C commitment, underscores the techno-utopian framing of the Paris Agreement. It is hard to underplay the fundamental reliance on the massive uptake of untried negative emission technologies to maintain the legitimacy of the Agreement. However and despite this reliance, there is no direct reference to such technologies throughout the thirty-one page document.

“If the global community is to maintain emissions with the 2°C carbon budget, there needs to be much greater recognition of the profound challenges we face. The scale of emission reductions will not be delivered through eloquent speeches, win-win rhetoric and green-growth spin. Zero carbon energy technologies are a prerequisite of a 2°C future – but they are far from sufficient. They will only deliver the necessary levels of mitigation if they are accompanied by fundamental changes to the political and economic framing of contemporary society. This is a challenge far beyond anything discussed in Paris – yet without it our well-intended aspirations will all too soon wither and die on the vine. We owe ourselves, our children and our planet more than that. So let Paris be the catalyst for a new paradigm – one in which we deliver a sustainable, equitable and prosperous future for all.”

“Some are saying that 1.5C is an impossible target – it is not. Ambitious but possible pathways that include large amounts of tree planting, bioenergy carbon capture and storage can get us there. If these are combined with cuts to short lived pollutants such as methane from agriculture and soot from diesel cars and cook stoves, we can get there. Realising this ambition is challenging, but if 196 countries can agree on the need, we should rise to the challenge.”

“This is obviously a significant result for action on climate change. It seems the case for change has been utterly accepted and there is now agreement on the level of the ambition required.

“Less clear are the details of how we will achieve what is necessary. While governments can set the conditions for the changes, those in innovation, education, finance, business and cities must now step up, plan ahead and work together to deliver our low carbon future.

“The last 10 years had seen a huge increase in climate change awareness by governments and non-government actors; we now need to work collectively on the solutions.”

Prof. Michael Grubb, Professor of International Energy and Climate Change at UCL, said:

“At 21, the global climate change regime has finally come of age. The Paris agreement is the best achievable. It completes the traumatic transition from a system that was deep but too narrow, to one that universalises the effort but is thus inevitably too shallow.

“The national goals to date do not yet come close to the agreed objective; the legal structure and the commitment to cycles of review and strengthening are pivotal. So make no mistake: this is the foundation of a globalised yet sufficiently fair response; it is not yet the house. On these foundations the house to avoid more dangerous climate change must now be constructed: country-by-country, region-by-region, and city-by-city – through all manner of coalitions ultimately to involve us all. And having achieved their most fundamental goal, the rich countries now carry more, not less, responsibility to help others, and to move deeper ourselves.”

Dr Jeffrey S. Kargel, Department of Hydrology & Water Resources at University of Arizona, said:

“The climate agreement is historic and far reaching, far beyond what I had imagined was politically possible. Such an agreement underscores the recognition by world leaders of the problems associated with climate change and the will to do something about it.

“The myriad and monumentally costly problems associated with climate change will be much reduced by this agreement. This concurrence by 195 nations seemed to me impossible – politically – to achieve two weeks ago, but here we have it…. something better than I had hoped was even possible. I am hopeful for the planet’s and our civilization’s future.

“The public, however, should understand that a great deal of climate change is already built into the human-modified Earth system. Climate change will continue, but now at a much reduced pace this century relative to what it would be without an international agreement and adherence to it. The public will hear continuing news about climate change for decades to come. Glaciers will continue melting, sea level will continue to rise, and extreme weather–including extreme hot spells, extreme droughts, extreme snowfalls and rain events– will continue to become shockingly ever more extreme. But the path our planet is on, with this agreement, if it is enforced, will be sustainable by civilization and most of nature.”

“In principle the Paris Agreement binds almost every country in the world to keeping global warming below 2 degrees above pre-industrial, with a target of 1.5 degrees above pre-industrial. Meeting this target will require fossil fuels to be kept in the ground, unexploited and stranded as assets – yet nothing is said on how this will be achieved. And with almost 1 degree of warming already ensured, there are very considerable grounds for scepticism about this “historic” agreement.”

Ajay Gambhir, Senior Research Fellow at the Grantham Institute for Climate Change and the Environment, Imperial College London, said:

“It is remarkable that a text of this ambition has been agreed by all Parties, given the much less ambitious options still on the table just three days ago. However, the gap between the agreement’s goal to limit warming to well below 2 degrees C and the current combined level of countries’ emissions pledges – which are not nearly enough to achieve this goal – means there is considerable work to do over the coming years.”

Prof. Daniela Schmidt, Bristol University, said:

“Limiting the rate and magnitude of climate change will have a large impact on the reaction of the world’s ecosytems. The challenge will be in everybody’s commitments to be visionary to achieve this goal.”

Prof. Richard Allan, Reading University, said:

“The human race has a climate crisis, Paris has delivered a plan, next begins the hard bit: action.”

Dr Ilan Kelman, University College London, said:

“The Paris outcome is momentous, but let’s not get too carried away. The initial draft’s limitations are not overcome, especially that key parts remain voluntary. Major hurdles still exist in countries taking forward this agreement – given that governments change and that strongly opposed interests have not disappeared. Then, we have implementation on the ground which will take years. Today is not the end, but the beginning of a journey which has already taken too long to start.”

“The new Paris Agreement is historic, important, world-changing and inadequate all at the same time. It is astonishing that all the countries of the world have agreed a pathway together to reduce greenhouse gas emissions. But the proof that this will happen will depend on policy changes. To meet a target of well below 2 degrees C above per-industrial levels will require leaving the vast majority of fossil fuel reserves in the ground. Will the deployment of renewable technologies be quick enough and cheap enough to keep fossil fuels in the ground? Personally I hope so. The proof will be whether globally investors shun fossil fuels and we soon see coal companies going out of business while investments in renewable technologies skyrocket.”

Prof. David Reay, Professor of Carbon Management, University of Edinburgh, said:

“This is a game-changer. The long nights of negotiations have paid dividends. Legally binding, a robust way to increase emissions reductions, and strong reporting requirements – really impressive. This agreement is the first concrete step on our collective way towards avoiding dangerous climate change. Paris already has the world’s sympathy, today it also has the world’s gratitude.”